The present invention relates generally to improvements in web handling and treating apparatus and it relates more particularly to an improved apparatus for heating an advancing thermoplastic film or pellicle attendant to its application to an article for packaging.
It is a common practice to package articles in a stretch type synthetic organic thermoplastic film and to this end the film is heated to a predetermined temperature immediately prior to its application to the article. The apparatus heretofore employed in preheating the film attendant to its application to the article possesses numerous drawbacks and disadvantages. It is generally a complicated and awkward structure of limited application and useful only with relatively narrow film of a restricted range and the heating and temperature control of the advancing film is usually poor. The precision of temperature control is low and excessive hunting often occurs so that a uniform optimum heating of the film is not achieved with the result that the packaging procedure and the quality of packaging are adversely effected. Furthermore, the speed of advance of the thermoplastic film is highly restricted thereby limiting the capacity of the apparatus and any machinery or operation with which it is associated.